By Kelly Hill
As the debate over whether terrestrial C-Band cellular networks can safely co-exist with aviation altimeters continues to play out — and carriers put off lighting up towers near some US airports to accommodate concerns about interference — Viavi Solutions says it has put together a testing set-up for 5G C-Band/altimeter interactions that draws on its experience in testing both avionics equipment and wireless telecommunications networks.
“Any potential [C-Band/aviation] interference would occur in a very narrow band of radio frequency, one that is technically not even part of the C-band (3.7-3.98 GHz) being utilized by communication service providers,” Viavi said in a release. It noted that the radar altimeter systems involved operate at 4.2-4.4 GHz, which in terms of radio frequency distance is several hundred megahertz away from current C-Band operations. However, the test company added, “there is potential for interference from the edges of these bands, which can be mitigated by testing and adjusting both 5G networks and [radar altimeter] systems prior to live deployment.”
Viavi’s testbed for these RF interactions consists of its OneAdvisor 800 site tester with real-time spectrum analysis; its Viavi ALT-9000, which it says provides altitude simulations with “true RF time delay and path loss models” to test radar altimeter (RADALT) systems and assess their vulnerability to potential 5G interference; and its Viavi Ranger, which records real-world 5G signals and plays them back into RADALT devices to simulate 5G C-band interference.
“At Viavi, we have a unique current understanding about potential interference in C-band, as we are deeply involved in both 5G communications and RADALT technologies,” said Viavi’s CTO, Sameh Yamany. “From this vantage point, we aim to help the industry and government regulators tackle any issues comprehensively, to enable communication service providers and aviation to operate harmoniously.”
The Federal Aviation Administration said last Friday that AT&T and Verizon operators provided more precise data about the exact location of wireless sites near airports of concern, which the FAA has used to map areas around airports that could potentially be affected and “[shrink] the areas where wireless operators are deferring their antenna activations.”
The agency added, “This will enable the wireless providers to safely turn on more towers as they deploy new 5G service in major markets across the United States.”
In other test news:
–Altice Labs is using Keysight Technologies’ O-RAN Radio Architect offerings to verify performance of Open RAN radio units (O-RUs). Portugal-based Altice Labs “is in the process of developing a portfolio of proprietary O-RAN radio units solutions,” Keysight said in a release.
Keysight also this week expanded its test capabilities for 800G connections in data center equipment.
-Signal booster company SureCall has released results from testing of its mmWave boosters, which are used in Verizon’s 5G network. At a total distance of 100 meters from the Horizon network booster – in an area where there was no Verizon 5G UWB signal without the Horizon – SureCall’s booster provided speeds of nearly 3 Gbps, the company reported. Full story is here.
–Charter Communications has been granted permission by the Federal Communication Commission to test 5G New Radio with a combination of 37 GHz and CBRS spectrum, using CBRS as an anchor. The tests will conducted at two outdoor sites in Castle Rock, Colorado, using multi-point to multi-point integrated antennas that will be mounted at a height of 133 feet on existing towers with a 50-degree tilt. Customer premise equipment mounted on the top of three vans will serve as the other end of the link.
–Anritsu unveiled new features for its MasterClaw 5G Standalone service assurance offering, including encrypted traffic monitoring capabilities from virtual Terminal Access Points (TAPs). It said that the availability of additional visibility into natively encrypted traffic in a 5G SA core network is “in cooperation with a major European Network Equipment Manufacturer.”
The virtual TAPs are integrated into the NEM’s virtualized network functions; Anritsu now provides a software option in its physical or virtual probes to take in Layer 7 traffic into its MasterClaw service assurance solution, which it says gives “an end-to-end consolidated view of the subscribers’ activity.”
“The 5G SA architecture brings many advantages, so Communication Service Providers are willing to deploy it as soon as possible in their live networks,” explained senior product manager for virtual probes and data acquisition at Anritsu, Angelo Baccarani. “However, these advantages come at the expense of added complexity in monitoring interactions between the Network Functions (NFs). This makes it difficult to guarantee that the subscribers will get the best Quality of Experience (QoS). One challenge is the encrypted nature of the communications between the 5G Core Network Functions in Service-Based Architectures (SBA). Network monitoring is made difficult, if not impossible. Anritsu now provides a solution to address this.”
–AT&T recently completed the first phase of a testbed related to the Department of Defense’s “smart warehouse” programme. In October 2020, the Department of Defense (DOD) announced US$600 million in awards for 5G experimentation and testing at five US military test sites, representing the largest full-scale 5G tests for dual-use applications in the world. AT&T recently demonstrated a private 5G network for DoD that achieved data throughput speeds greater than 4 Gbps with less than 10 milliseconds of latency using AT&T 5G spectrum and a private 5G core and Radio Access Network (RAN). That testing was at a testbed facility in Richardson, Texas; the next phase involved providing 5G at a 120,000 square foot warehouse at Naval Base Coronado.
